a. Field of the Invention
This invention relates to a method of revising a profile generated using figure definition statements in an automatic programming language, and more particularly, to a profile revising method for revising an already defined profile and for suitably revising a corner shape such as a chamfered or rounded shape contained in the profile.
b. Description of the Related Art
In an automatic programming system for creating NC data using an automatic programming language such as APT (automatic programming tools) or FAPT,
(a) a part program based on the automatic programming language is created by defining points, straight lines and circular arcs using simple symbols (this is referred to as "figure definition"); defining a profile using the defined points, straight lines and circular arcs (referred to as "profile definition"); and then defining a tool path along the profile (referred to as "motion statement definition"), and
(b) the part program based on the automatic programming language is subsequently converted into NC data comprising NC data (EIA codes or ISO codes) in a format capable of being executed by an NC unit.
For example, in order to define figure elements S.sub.1 -S.sub.4 shown in FIG. 9 and subsequently insert rounded arcs of radii r.sub.1, r.sub.2 at a corner portion CN.sub.1 of sides S.sub.2, S.sub.3 and a corner portion CN.sub.2 of sides S.sub.3, S.sub.4, respectively, as shown in FIG. 10, to define a profile A.sub.0, the following is entered using the defined figure element symbols S.sub.1 -S.sub.4 : EQU S.sub.1 EQU S.sub.2, r.sub.1 R EQU S.sub.3, r.sub.2 R EQU S.sub.4 EQU S.sub.1
The alphabetic character "R" means that a rounded shape having a prescribed radius r.sub.i is inserted at a corner.
In order to insert chamfered portions having amounts of chamfer c.sub.1, c.sub.2 at corner portion CN.sub.1 of sides S.sub.2, S.sub.3 and corner portion CN.sub.2 of sides S.sub.3, S.sub.4, respectively, as shown in FIG. 11, to define a profile A.sub.1 after the figure definition of FIG. 9 is made, the following is entered using the already defined figure element symbols: EQU S.sub.1 EQU S.sub.2, c.sub.1 C EQU S.sub.3, c.sub.2 C EQU S.sub.4 EQU S.sub.1
The alphabetic character "C" means that a chamfered shape having a prescribed amount of chamfer c.sub.i is inserted at a corner.
More specifically, the already defined figure elements are arrayed in order along the profile. When rounding is to be performed, rR (r represents the radius) is disposed between the two straight-line symbols indicating the two straight lines where the rounding is to be inserted. When chamfering is to be performed, cC (c represents the amount of chamfer) is disposed between the two straight-line symbols indicating the two straight lines where the chamfer is to be inserted.
In a profile in which a chamfered or rounded corner portion has been inserted, there are cases where it is desired to revise a figure element other than that of a corner shape. Since the profile is changed by the revision in such case, a situation may arise in which an error is generated because the chamfered or rounded corner shape which until now could be inserted between sides of the profile can no longer be inserted.
For example, if the figure element S.sub.1 of the profile A.sub.0 defined in FIG. 10 is revised to the figure element S.sub.1 ' shown in FIG. 12, the rounding arc of radius r.sub.1 cannot be inserted at the corner portion CN.sub.1 between the sides S.sub.2, S.sub.3 merely by a revising operation in which the figure element S.sub.1 is replaced by the figure element S.sub.1 '. In other words, the rounding arc of radius r.sub.1 cannot be inserted at the corner portion CN.sub.1 so as to contact the sides S.sub.2, S.sub.3. An error is generated as a result.
In the prior art, however, the location at which the error will occur cannot be determined from the profile definition statements on the revision display screen. As a result, the operator is constrained to check, by repeated computations, whether an error has occurred at rounding between sides, and to subsequently revise the rounding radius at the location of the error. As a consequence, checking error locations consumed large amounts of time. Though the foregoing relates to rounded corner portions, the same holds true at chamfered corner portions.
Further, the revision screen and an execution screen displaying the profile are separate screens in the prior art. Therefore, when an error occurs, a revision must be carried out by switching back and forth between the execution screen and the revision screen. This is a troublesome task.
Accordingly, an object of the present invention is to provide a profile revising method in which revision of a profile can be executed without being aware of the presence of chamfered or rounded corner shapes, in which the location of an error can be clarified when an error occurs due to a revision, and in which revision of a profile and display of the profile can be performed on the same screen.